High-frequency alternator



E. F. W. ALEXANDERSON.

HIGH FREQUENCY ALTERNATOR.

APPLICATION HLEU NOV. 4. 1918.

1,369,601. Patented Feb. 22,1921.

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rotor slots.

UNITED srATEs PATENT OFFICE.

ERNST F. W. ALEXANDERSON, OF SCHENEC'IADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

HIGH-FREQUENCY ALTERNATOR.

Specification of Letters Patent.

Patented Feb. 22, 1921.

Application fled November 4, 1918. serial 80. 280,991.

To all whom it may concern:

Be .it known'that I, ERNST F. W. ALEX- ANDERSON, a citizen of the United States, residing at Schenectady in the county of Schenectady, State of New York, have invcntcd certain new and useful Improvements in l'ligh-Frequency Alternators, of which the following is a specification.

My invention relates to high frequency iilternators, and particularly to the type of altcrnators disclosed in United States Letters Patent No. 1,008,577 and No. 1,110,029, issued in my name.

The objects of my present invention are to provide an improved construction for such type of alternator whereby a more cfiicient, rugged and more easily manufactured machine is produced than formerly.

More especially, the objects of this invention are to improve the structure of the rotor, or inductor, so as to provide a more eflicient distribution of the magnetic and nonmagnetic material thereon, without impairing an of the mechanical properties thereof.

n carrying this invention into efiectyl provide two circumferential rows of radial slots in the inductor-andarra'nge inserted material in these two circumferential rows of slots in order that the strainsoceasioned by the retaining of this inserted material in place. are not wholly sustained by the outer rim of the rotor but are distributed over an inner as well as the outer rim.

For a further understanding of the nature and objects of this invention reference should be had to the following detailed description taken in connection with the accompanying drawing, in which;

Figure 1 is a vertical cross section of the upper half of a high frequencyalternator em 'iodying my present invention; Fi s. 2 and 3 are enlarged fragmentary views s owing details in the rotor constructionrvand Fig. 4 is a perspective view showing details in theform of the material inserted in the Referring now to'Fig. 1; 1 denotes the stator into which are screw-threaded a air of ring shaped members 2-2. Each of t ese members carries a circumferentially extending" laminated ring 3 clamped between two rings-,4. These laminated rings constitute pole-pieces between which the inductor member or rotor 5 revolves, the excitation for these rings being-provided by the field windings 6, the magnetic circuit being arranged to surround these windings and pass through the rings 3 and the inductor mem- The air aps between the inductor mem ber 5 and t c rings 3 rein the present case bounded by the conica surfaces whose spices lie in the axis of the rotor, and which de fine the taper on the edge of the inductor member and the configuration of the adjacent surfaces of the rings 3. My invention, however, is not limited to this particular form of invention.

The width of this air gap may be adjusted by rotating the ring-shaped members 22 in the stator 1; securing means shown at 20 being provided to hold these members 2-2 in their adjusted position.

The inductor member 5'has its edge out through symmetrically from each side so as to form two circumferential rows 7 and 8 of radial slots having central rid es such as indicated at 9 in Fig. 2. The in uctor member 5 is preferably made of ma etic material, conseguen'tlyl have rovi ed a filler 10 of non-magnetic materia such as copper or non-magnetic alloy for the slots formed in the'rim. The filler IOpreferably comprises three part-s11, '12 and 13, two of which namel 11 and 13, are made of forgings desi ac to fit into the four corners astride o the ridges 9.' The third piece 12 is a wedge-shaped forging designed to be in-; sorted between pieces 11 and 13 in order to force them snugly into the corners thereby completely filling each slot. These forging's may be secured in the slots in an convenient mannen'for instance, by slight y upsettin the edge of the forgings along the edgeo the slots. v, The inner rim, shown clearly 'at 14, is preferably made narrow so that the upper row of inserted material may join the lower. row, whereby the inner andouter radial inserts act as a single insert to permit ammo economical use of the copper in the armature windings. The armaturewindings are in dicated at 15 and are fitted into radial slots formed in the face of the laminated riii '3. Any desired arrangement of these win mgs. 1015 may be adopted but one avoiding pulsations in the magnetic flux would of course be preferred, such as I have disclosed in the aforementioned patents.

In operation, the rotor is rotated at such velocity that the alternate changes in the density of the flux threading through the armature winding 15 occasioned by the movement of the inductor member there across, induces an E. LLF. having the desired periodicity in the windings 15.

Among the advantages accruing from my im roved'rotor construction is t no greater ra ial length of inserted material which may be .used in the active portion of the inductor member without putting undue mechanical strains in the spokes thereof, and the facility with which the. slots may be milled from each side, leaving the central ridges resulting in a reduced cost of manufacture.

'While I have here shown an embodiment of my invention which is at present, the best means known to me for carrying the same into effect, I would have it understood that this is merely illustrative and that I do not mean to be limited thereby to-the precise details here disclosed since obvious alterati'ons thereof will appear to those skilled in this art, nor in the choice of recognized equivalents except as defined in my claims hereunto annexed.

What I claim as new and desire to secure by Letters Patent of the United States, is

- 1. A- high frequency alternator comprisin a stator carrying a pair of circumferentia ly extending laminated rin having opposin faces,awindin carried ysaid faces, an in uctor member adapted to he rotatively moved between said faces, said member being formed with two circumferential rows of radial slots, and fillers disposed in said 5 ots.

2. A high frequency alternator comprising a stator carrying a pair of circumferentially extending laminated rings havin opposing faces, a. winding carried by sai faces, an inductor member adapted t'o'be rotativel moved between said faces, said memher being formedof nmgnetic material with two circumferential rows of radial slots, and fillers of non-magnetic material disposed in said slots so that the upper and lower rows join to form continuous radial inserts.

3. A high frequency alternator comprising a stator carrying a pair of circumferentially extending laminated rin having opposing faces, a winding carrier by said faces, and inductor member adapted to be rotativel moved between said faces, said member being formed. of magnetic material with two circumferential rows of radial slots, symmetrically cut from both sides and having central ridges, and fillers of nonmagnetic material disposed in said slots astride said ridges.

4, A high frequency alternator comprising a stator carrying a pair of circumferentially extending laminated rings having opposing faces, a winding carried by said faces, an inductor member ada ted to be rotatively moved between sai faces, said member being formed of magnetic material with two circumferential rows of radial slots and fillers of non-magnetic material each composed of a plurality of parts inserted in said slots so as to completely fill each slot.

5. A high frequency alternator comprising a stator carrying a. pair of circumferentially extending laminated rings havin opposing faces, a winding carried by sai faces, an inductormembcr adated to be rotatively moved between sai faces, said member being formed of magnetic material with two circumferential rows of radial slots having .central ridges, and fillers of non-magnet1c material each composed of three parts two of said parts each being formed to fit astride one of said rid es and the third bein adapted to wedge tie first two parts in p ace.

6. A high frequency alternator comprising a stator carrying a pair of circumferentially extending laminated rings havin opposing faces, a winding carried by sai faces, an inductor member ada )ted to be retatively moyed between sai faces, said member being formed of magnetic material with two circumferential rows of radial slots having central ridges, and fillers of non-magnetic material each composed of a plurality of arts wedged in said slots astride said ridges so that the upper and lower rows join to form continuous radial inserts.

7. A high frequency alternator comprising a stator carrying apair of circumferentially extending laminated rin s having opposing faces, a. winding carrie by sai faces, an inductor member adapted to be ro tatively moved between said faces, said member being formed of magnetic material with two circumferential rows of radial slots symmetrically cut from both sides and having central ridges, and fillers of nonmagnetic material each'composed of three parts inserted in said slots so that the u per and lower rows form continuousradia inserts, two of said partseach being formed to fit astride said ridges-and the third being wedged between t the filler is retained in a manner completely filling the slot.

In witness whereof I have hereunto set my hand this first da of November 1918.

' ER! 1' F. W- ALEXANDERSON.

e first two whereby 

